code: def testEmptyVectorInMatrix(self):
      p = Pool(
          {"foo": [[4.489, 22.0, 7.0], [], [89.153, 0.134, 10.1544564]]}
      )
  
      results = PoolAggregator()(p)
  
      # should result in no aggregation of the 'foo' descriptor
      self.assertEqualVector(results.descriptorNames(), [])
  
file_path: essentia/test/src/unittests/stats/test_poolaggregator.py
imports: from essentia_test import *
label_desc: Use image node_id 7 for calling the TestPoolAggregator obj's underlying member method code with example usage: obj.testEmptyVectorInMatrix() without return types